Mobile virtual network operator (MVNO) is the term referring to a wireless carrier that provides communication services to their customers by using a network infrastructure, not of their own, but leased from a mobile network operator (MNO). For example, an MVNO carrier leases a radio access network such as a Long Term Evolution (LTE) network from an MNO to permit their service users to make a link connection from their mobile stations to the MVNO's own network. Content servers are deployed on this MVNO network to provide the users with various services.
As an example of conventional techniques, several researchers propose a system and method for automatically and dynamically initiating and establishing secure connections between a server and a client using a session control server. See, for example, Japanese National Publication of International Patent Application No. 2008-505512. As another conventional technique, a system and a method are proposed for enhancement of electronic security. As yet another conventional technique, a network management method is proposed for managing network devices with dynamic IP addresses. As still another conventional technique, a computer-based technique is proposed for processing end-to-end business transactions in a Transmission Control Protocol/Internet Protocol (TCP/IP) environment.
As mentioned above, the radio access network of an MNO is connected to a remote network (e.g., MVNO network). A router or gateway is placed at the point of interface between those two networks, and it is this interface device that controls connection and disconnection of communication links from mobile stations to the remote network. For this reason, servers on the remote network are unable to recognize disconnection of a link of a mobile station that they are serving.
When a link connection from a mobile station to the remote network is successfully created, the mobile station then establish a session with a server on the remote network. However, the above-noted interface device is not involved in the control process of establishing and releasing such sessions. This means that the session of a mobile station could remain in an active state even after the link between the mobile station and remote network is disconnected.